Focusing lamp



Jan. 18, 1927. 1,614,729

C. E. GODLEY FOCUSING LAMP Filed Sept. 28, 1925 E e/7 ta -J I CGF/Cj GZJ /I 6W 0%2 Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

CHARLES E. GOIJLEY, OF DETROIT, MICHIGAN, ASSIGNOB, BY MESNE ASSIGNMENTS, TO 0. M. HALL LAMP COMPANY, A CORPORATION OF MICHIGAN.

FOCUSING LAMP.

Application filed September 28, 1925. Serial No. 59,036.

- My invention relates to projecting lamps, and in its general objects aims to provide a lamp construction in which the lamp socket is fulcrumed on the reflector and is adjusted in position by means which are mounted on the back of the lamp casing and conveniently accessible from outside the lamp casing.

Moreover, my invention provides a construction for this purpose which will be simple, inexpensive and easily manipulated; also, one which can readily be employed with lamp bodies of widely different shapes and with widely differing spacings between the back of the lamp and the reflector. Further and also more detailed objects will appear from the following specification and from the accompanying drawings.

In these drawings, Fig. 1 is a central and longitudinal section through an automobile headlight embodying my invention and employing a parabolic reflector, showing the socket as disposed coaxial with the reflector.

Fig. 2 is a rear view of the central port-ion of the back of the lamp casing in Fig. showing the focusing means as they appear when the socket has been tilted laterally out of axial alinement with the reflector.

Fig. 3 is an enlarged rear view of the central portion of the reflector.

Fig. 4L is an enlargement of a left-hand portion of Fig. 1.

Fig. 5 is a fragmentary View similar to a portion of Fig. 1, showing my invention as employed with an elliptical reflector within an elliptical casing.

Referring first to Fig. 1, this shows a lamp having a forwardly open casing closed by a door 1 which includes a lens 2. This lens bears against a packing ring 3 carried by a parabolic reflector 4 which has its rim engaging an annular shelf 5 formed on the lamp body at the mouth of the latter. The reflector 4 has the usual axial perforation through which the lamp socket 6 extends, and has the portion surrounding this perforation formed into spring fingers 7. These fingers preferably are curved rearwardly of the general curvature of the reflector, as shown in Fig. 3, and are so formed as to grip the shell of the socket frictionally with a. pressure which will still permit both a longitudinal sliding of the socket and a tilting of the socket out of axial alinement with the reflector.

The back 8 of the lamp body or casing has the portion adjacent to the axis of the reflector curved to form a portion of a sphere which has its center at the center 9 of the socket-gripping portions of the spring fingers at the rear end of the reflector. Mounted on this spherically curved portion of the back of the lamp casing is a clamp comprising a pair of correspondingly curved clamping plates 10 and 11 which are respectively disposed inside and outside the said back. These plates are connected by screws 12 extending through perforations in the lamp back, the perforations being considerably larger in diameter than the shanks of the screws so that the screw-connected plates can be slid in any direction when the screws are relaxed.

To prevent the outer clamping plate 11 from damaging the enamel or other finish on the lamp back 8 when it is thus slid, I preferably interpose between them a rub plate 13 of larger diameter than the outer plate 11. This rub plate is anchored to the lamp back 8 to prevent it from being slid along with the outer plate, as for example by forming forwardly directed annular flanges 14: on it which interlock with the bores of the perforations through which the screws extend, as shown in Fig. 4.

Swiveled upon one of the clam plates, and desirably on the outer plate 11, is an adjusting screw 15 which is threadedly connected to the lamp socket 6, as for example by threading the screw through the bight of a yoke 16 rigidly secured to the shell of the socket. To afford the said swiveling connection, I desirably extend the shank o the screw through a perforation in the outer plate 11 which closely approaches the screw shank in diameter, and interpose a compression spring 17 between the said outer plate and the bight of the yoke. Thus arranged, the spring not only draws the head of the screw firmly forward against the outer clamping plate, but also presses the yoke forwardly so as to take up any backlash in the threaded connection of the screw to this yoke. By so doing I secure a firm connection between the outer clamping plate and the socket, so that in view of the screw connections between the two clamping plates 11 and 10, these clamping plates are always coaxial with the socket.

By rotating the screw 15 in either direction, the socket 6 and the lamp bulb 16 carriedby. thelatter may be moved forward or backward. Likewise, when the screws 12 are relaxed, the interconnected clamping plates can be slid in any direction transversely of the axis of the reflector, thereby rocking the socket about its fulcruming engagement with the spring fingers of the reflector and moving the lamp filament correspondingly. Then a retightening of the screws 12 will lock the interconnected clamping plates (which, together with the two screws comprise the clamping member of my focusing lamp) in the adjusted position, while the pressure of the spring 17 at all times holds the screw 15 in its adjusted position.

By employing the lamp back and the re-' flector perforation wall as supports for parts 'of the focusing arrangement, I-provide a simple and inexpensive construction without requiring an unusually high degree of accuracy in the fitting of the various elements. So also, I provide a focusing arrangement which can easily be manipulated even by inexperienced users, and one which can readily be employed with varying spacings between the reflector and the lamp back by correspondingly varying the joint effective length of the screw 17 and the yoke or other soc-ket'supported part into which the screw is threaded.

Moreover, the presented arrangement can obviously be employed with various shapes or reflectors and lamp casings. For ex ample, F 5 shows the rear portion of another lamp embodying my invention and employing an elliptical reflector-housed by an elliptical casing. Hence I do not wish to be limited to the particular shapes of lamps here disclosed, or even to the mounting of the clamping member on the back of the lamp casing, since any spherically curved member spaced rearwardly from the reflector and rigid with respect to the reflector will serve the same purpose. Nor do I wish to be limited to the details of construction and arrangement here disclosed, as many changes might be made without departing from the spirit of my invention or from the appendedclaims.

I claim as my invention 1. In a focusing lamp, a reflector having an axial rear perforation, a member having spherically curved portion fixedly disposed behind the reflector and provided with a perforation coaxial with that in the reflector, the center of the spherical curvature being substantially at the center of the perforation in the reflector, a clamping member slidably mounted on the spherically curved portion for movement transversely of the axis of the said perforations, a lamp socket extending through and fulcrumed in the perforation in the reflector, and connecting means interposed between the clamping member and the socket, the said means including an element swiveled upon one and having threaded connection with the other of the parts connected by it, the clamping member including a pair of plates respectively disposedin front of the said metal member and behind the latter; and the connecting means comprising a yoke fast upon the socket, a screw extending freely through both of the said plates and threaded through the yoke and a compression spring interposed between one of the said plates and the yoke.

2. In a focusing lamp, a reflector having an axial rear perforation, a member having a spherically curved portion fixedly disposed behind the reflector and provided with a perforation coaxial with that in thereflector, the center of the spherical curvature being substantially at the center of the perforation in the reflector, a clamping member slidably mounted on the spherically curved portion for movement transversely of the axis of the said'perforations, a lamp socket extending through and fulcrunied in the perforation in the reflector, and connecting means interposed between the clamping member and the socket, the said means including an element swiveled upon one and having threaded connection with the other of the parts connected by it; the portion of the reflector adjacent to the perforation in latter being slitted to afford rearwardly extending spring fingers each bowed in a plane radial of the perforation and convexed toward the axis of the perforation and each having its bowed portion engaging the socket to fulcrum the latter.

Signed at Detroit, Michigan, September 24,1925. 1

CHARLES E. GODLEY. 

